Pallets are universally used in virtually all industries. Most industrial pallets are rigidly constructed of wood. However, other materials such as plastic, metal, paper and recycled materials have also been used in their construction. Each material has advantages and disadvantages relative to the others and to their respective intended uses. Most industrial pallets are designed to be lifted and moved by means of a Forklift and/or hand operated pallet jacks. Most pallets have a generally planar upper deck surface for supporting the load to be carried by the pallet.
Wooden pallets are susceptible to bacterial and chemical contamination that can be problematic in food and produce transportation. They also exhibit relatively poor resistance to weathering, rot and chemicals, and are subject to splintering and dislodgement of nails and staples used in their construction. However, since they are relatively lower in cost than alternatively constructed pallets, wood pallets are most commonly used. Steel pallets are strong and used for heavy and/or highly stacked loads. However, they have a higher initial price, are significantly more heavy than wooden pallets, and when made from carbon steel, are susceptible to rusting. Aluminum pallets are stronger than those of wood or plastic, are lighter than steel and resist weathering, rotting, plastic creep and corrosion and are good for air freight and sea storage applications. Paper pallets are often used for light loads and can be recycled for easy disposal. They are cleaner, safer and can provide a cost saving, eco-friendly alternative to other pallet materials. However, they are subject to weathering and moisture that weakens their structure.
Although wooden pallets come in many sizes and configurations, they generally fall into two very broad categories, generally referred to as stringer pallets or block pallets. Stringer pallets generally have a lower support structure of three or more continuous, longitudinally extending solid or notched wooden beams which support upper deck board components nailed perpendicularly to and across the lower beams. The upper deck boards are often identified by their location, as for example “outside” or “center” stringers. Block pallets are those which have wooden blocks between upper deck boards or between upper and lower decks. A pallet with top and bottom decks are referred to as “double face pallets”. Pallets are also referred to as “two way” or “four way” pallets which refers to the number of directions from which they can be lifted using Forklift or hand pallet jacks.
A number of different organizations and associations work towards establishing and promogating standards for pallets. Some strive to develop standards for pallet dimensions or materials used in their construction. Others focus on standards for a specific industry or type of load material being carried by the pallet. Companies utilize hundreds of different pallet sizes and use both stringer and block pallets to meet specific end user requirements. In the United States, stringer pallet constructions basically follow the GMA (Grocery Manufacturers Association) standards. Block pallet configurations typically follow the standards of the pallet rental companies regarding packaging, palletizing, warehousing and transportation. For example, the beverage industry segment uses a 48″ by 42″ pallet. No single dimensional standard governs pallet production, since the size of pallets differ from and are favored by one industry as compared to another. For example, the most common footprint size of a pallet used by the Grocery Food industry, and many others, is a 48″ by 40″ pallet. There are basically twelve different industries in the United States that utilize a common size, and the most used pallet in North America is the wooden 48″×40″ pallet.
The rigid construction of known pallets does not readily lend them to be easily disassembled for collapsibility or for replacement of worn or damaged parts of the pallet. Further, in certain pallet use situations such as for the transport of bulk material containers housing flowable or semi-fluid materials such as chicken or other meat, the pallet or its use can contribute to contamination of the bulk material. For example, bulk material containers carrying 2,000 lb. loads of semi-fluid chicken are typically carried by wooden pallets having spaced wooden slats forming their upper deck surface. To empty the container at the meat processing plant, the pallet and bulk container are tipped (rotated) to allow the container contents to flow into an underlying receptor. In the process, dirt carried by or on the pallet and/or loose portions of the pallet such as wooden splinters, nails and staples, can be deposited along with the meat, thereby contaminating the food product. Storage and/or transport and handling of used pallets back to an industrial loading location can also be expensive due to their size and rigid construction.
The present invention addresses the above industry needs by introducing an improved pallet configuration having an interlocked top deck and frame construction that provides structural strength to the pallet and enables reduction in the number of top deck boards, and one that enables the pallet to be collapsed and folded into a compact configuration for transport and storage when not in use, and readily reassembled for subsequent use. The improved pallet also provides improved sanitation to the load being carried by the pallet besides providing handling, storage and shipment efficiency and cost savings to the pallet manufacturer, distributor and the end customer.